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The goal of this systematic review is to investigate the applicability of the results from existing life cycle analysis (LCA) and environmental assessments studies in informing nutritional strategies for environmentally sustainable poultry meat production. This paper reports on a Rapid Evidence Assessment (REA) of articles published between 2000 and 2020. The studies reviewed were conducted in developed countries including UK, France, Germany, Sweden, Norway, The Netherlands, Denmark, Belgium, Canada, and USA. All articles were written in English. The REA includes studies on LCA of differing strains of meat poultry and production systems, studies on poultry manure emission and studies on environmental assessments of plant-based feed ingredients. The review covered studies on soil carbon dynamics associated with plant-based ingredients. Web of Science, Scopus, and PubMed were used to obtain the 6,142 population articles. The multistage screening process resulted in 29 studies from which 15 studies included LCA while the rest 14 studies analyzed NH 3 emission of broilers. All studies based on LCA were descriptive and did not include replications. Only 12 studies assessed the effect of interventions to reduce NH 3 emission of broiler litter using replicated layout designs. It is concluded that the broiler industry in UK, EU, and North America cannot rely on results of existing LCA and environmental assessments studies to inform their nutritional strategy and poultry meat production due to a shortage of reliable in vivo data assessing interventions in controlled studies. [ABSTRACT FROM AUTHOR]

"What are you going to do next?" is a common question often asked of a student who has recently graduated with either an MSc or PhD degree. We should not be surprised to hear the answer "I do not know yet." I have talked with many poultry science graduate students who usually start thinking about their future careers a few months before defending their thesis. I personally believe that nothing happens overnight in this world (excluding political-related issues), so we as graduate students need to have a comprehensible and pragmatic strategy when it comes to answering the question "What to do next?" This paper is not about how graduate students can find a job because there are numerous sources of information that are readily available elsewhere. One of the key messages of this paper is that networking is of paramount importance when it comes to moving in the right direction after graduation. Consequences of any decision made at this stage will often have a far-reaching unseen influence on us for many years into the future. I am also fully aware that there are many things over which we do not have any control, but as graduate students, are we doing our best to prepare ourselves for the real world? [ABSTRACT FROM AUTHOR]

"Continuous feeding of low concentrations of sulfaquinoxaline for the control of coccidiosis in poultry" by L. C. Grumbles, J. P. Delaplane, and T. C. Higgins [Poult. Sci. (1948) 27:605-608] was the first paper to demonstrate that it was possible to control coccidiosis by the continuous inclusion of a low level of a drug in the feed of chickens. The principle involved (prevention or prophylaxis) has had a profound impact on our ability to grow chickens and turkeys under intensive conditions. Indeed, it is possible that the modern poultry industry could never have developed to its present extent without the advent of drugs used prophylactically to control coccidiosis. One particular insight was that use of a compound in this manner did not necessarily prevent the acquisition of immunity, an important principle that helpsexplain the continued efficacy of ionophorous antibiotics used today. The significance of this work to the poultry industry and individuals involved in research, whether employed by government, academia, or pharmaceutical companies, cannot be overstated. Economic benefits, in terms of improved productivity, have been demonstrated in numerous studies published in Poultry Science. In addition, the livelihoods of many poultry farmers have been helped by the control of a disease that in the past caused substantial morbidity and mortality in their flocks. The paper is brief and contains no critical science involving novel procedures but has had a profound influence on the health of poultry for the last 6 decades. For this reason, it is nominated as a landmark contribution from the first 100 yr of Poultry Science. [ABSTRACT FROM AUTHOR]

Pickled eggs enjoy a long processing history with unique flavor and rich nutrition but suffer from long pickling cycle due to the limitations of traditional processing methods. In terms of quality, salted egg whites have the disadvantage of high sodium content, and salted egg yolks have problems such as hard core and black circle around outer layer. Likewise, the quality of preserved eggs is challenged by the black spots (dots) on the eggshells and the high content of heavy metals in the egg contents. The sustainable development of traditional pickled eggs are hindered by these defects and extensive research has been carried out in recent years. Based on the elaboration of the quality formation mechanism of salted eggs and preserved eggs, this paper reviewed the processing principles and applications of rapid pickling technologies like ultrasonic technology, magnetoelectric-assisted technology, water cycle technology, vacuum decompression technology, and pulsed pressure technology, as well as the quality optimization methods such as controlling the sodium content of the salted egg whites, improving the quality of salted egg yolks, promoting the quality of lead-free preserved eggs, and developing heavy metal-free preserved eggs. In the end, the future development trend of traditional pickled eggs was summarized and prospected in order to provide theoretical guidance for the actual production. [ABSTRACT FROM AUTHOR]

In broiler breeder production, up to 2% of hatching eggs are rejected because of cracked or broken shells. Eggs with cracks give a reduced hatchability and a lower chick quality and cause economic loss. The main goal of this study was to determine the effect of sealing eggshell cracks with surgical tape on hatching parameters. A total of 3,000 eggs from a 34 weeks old Cobb 500 broiler breeder flock was used in the experiment. Six hundred intact eggs represented a positive control. Other eggs were artificially cracked by the operator either on the first day of storage (1,200 eggs) or on the fourth day of storage (1,200 eggs). In both groups, cracks on 600 eggs were sealed by the adhesive surgical tape while the other 600 eggs remained untreated and were used as a negative control. Within each experimental group, eggs were assigned randomly to 4 setter trays representing 4 replicates of 150 eggs. The egg weight loss during incubation was the highest (P < 0.01) in groups of nonsealed cracked eggs. The egg weight loss in sealed groups was higher compared to the control group (P < 0.01). Percentage of egg contamination was not different between groups. Embryonic mortality was higher in non-sealed groups in all stages of embryonic development (P < 0.01) compared to groups of sealed cracked eggs and the control group. Hatching percentage was significantly lower in non-sealed groups (P < 0.01) compared to sealed groups and positive control. No significant difference in hatching parameters was observed between sealed groups and positive control, indicating that surgical tape can be used for sealing cracks on the eggshell to support embryonic survival. [ABSTRACT FROM AUTHOR]

Identification and quantification of stress and stress inducing factors are important components of animal welfare assessment and essential parts of poultry management. Measurement of the autonomic nervous system's influence on cardiac function using heart rate and heart rate variability (HR/HRV) indices can provide a non-invasive assessment of the welfare status of an animal. This paper presents a preliminary study showing the feasibility of continuous long-term measurement of HR/HRV indices in freely moving chicken. We developed and evaluated an electrocardiography (ECG) based HR/HRV recording system that can be used as a poultry wearable backpack for research studies. The backpack system was first validated against a commercial ECG amplifier, and the corresponding estimations of HR values matched well with each other. Then, an in vivo proof-of-concept experiment was conducted on floor-reared chickens to collect ECG data for 2 weeks. The extracted HR/HRV values show strong alignment with circadian patterns and well-defined sleep cycles. Wearable devices, like the backpack ECG system used in this study, may be best suited for application in freely moving poultry to get an insight into circadian abnormalities and sleep quality for stress and welfare management. [ABSTRACT FROM AUTHOR]

Up to now there is no economically maintainable modality for chicken sexing in early embryonic stages (first 3 d) that is suitable for large-scale application in the commercial hatcheries. Hence, the culling of male day-old chicks of layer lines is still the normal procedure. In this paper we present a non-destructive optical technique for gender determination in layer lines with gender-specific down feather color. This particular chicken strain presents a sexual dimorphism in feather color, where the female day-old chicks have brown down feathers and the males have yellow down feathers. The eggs are candled with halogen lamps and a hyperspectral camera collects the transmitted light within the spectral range from 400 nm to 1,000 nm. For data analysis and classification, common methods like principal component analysis and linear discriminant analysis are used. The accuracy of gender determination was determined for 11- to 14-day-old embryos. At 14 d of incubation (7 d before hatch) the sex can be determined with an overall accuracy of approximately 97%. [ABSTRACT FROM AUTHOR]

Chicken IgY has been applied in the food industry as an important supplement. Glycation of IgY is of special interest due to its possible influence on the structure and functionality of IgY. IgY was subjected to in vitro glycation with 4 different monosaccharides, including glucose (Glu), mannose (Man), fucose (Fuc), and fructose (Fru). The objective of this paper was to characterize the formation of IgY-sugar conjugates using ultraviolet spectra, fluorescence spectra, circular dichroism spectra, Fourier transform infrared spectra, and SDS-PAGE and differential scanning calorimetry analysis. The antigen epitopes of native and glycated IgY was determined by enzyme-linked immunosorbent assay (ELISA). The existence of broad bands in stacking gel and sample well demonstrated that reducing monosaccharides covalently bound to IgY. The secondary structure of IgY was altered from a well-defined β-sheet structure to a random coil structure. Fluorescence spectra showed that IgY was more hydrophilic after glycation. Thermal stability of glycated IgY was remarkably increased over that of native IgY. However, ELISA results would suggest that the antigen epitopes recognized by the polyclonal antibody and overall conformation changed in the IgY molecule due to a decrease in polyclonal antibody binding to glycated IgY. Data suggested that glycation induced by reducing sugars significantly affects the structure and antigen-binding ability of IgY, which could reduce the utility of IgY in certain applications. [ABSTRACT FROM AUTHOR]

Next-generation sequencing technologies have become a powerful tool for the analysis of microbial communities. Sequencing of the hypervariable regions of the 16S ribosomal RNA gene following the amplitag amplification process has allowed the study of the diversity of samples of diverse origin. According to previous reports, the number of sequences required for the correct determination of the composition of a given sample may vary with the degree of diversity of that sample. In this paper, we investigate the correctness of comparing heterogeneous size datasets of bird intestinal microbial communities obtained from pyrosequencing data (Roche 454 technology) without prior normalization. We conclude that the differences observed between samples are due mainly to individual differences, not to differences in the number of readings in each sample, which makes data normalization unnecessary with the conditions described here. [ABSTRACT FROM AUTHOR]

The University of Georgia maintains two meat-type chicken control strains: the Athens Random Bred (ARB) and the Athens Canadian Random Bred (ACRB). The Athens Random Bred was developed from colored plumage commercial meat chicken strains in 1956. The ACRB is a replicate population of the Ottawa Meat Control strain which was developed in 1955 from white plumage commercial meat-type chickens. These genetic lines have been extremely valuable research resources and have been used extensively to provide comparative context to modern meat-type strains. The ACRB may be the oldest pedigreed control commercial meat-type chicken still in existence today. This paper reviews the history of the breed backgrounds for both control populations and reviews research utilizing the ACRB. [ABSTRACT FROM AUTHOR]

Levels of natural antibodies (NAb) binding keyhole limpet hemocyanin (KLH) in layers were shown to be heritable and to be potential indicative parameters for survival. A proportion of NAb are directed to self-molecules, or slightly changed selfmolecules (neo-epitopes), labeled as natural autoantibodies (NAAb). It is unknown whether the levels of NAAb are heritable and genetically correlated. In this paper, we estimated genetic parameters in plasma of healthy layers for IgM and IgG antibodies binding ovalbumin (OVA), myosin (MYO), cardiolipin (CAR), lysozyme (LYS), and the model antigen keyhole limpet hemocyanin (KLH). A linear animal model was used to estimate (co)variance components, heritabilities, and correlations. The estimates of heritabilities ranged from 0.10 to 0.17 for IgM, and 0.02 to 0.11 for IgG, respectively. For both IgM and IgG, high genetic correlations were observed between levels of NAAb binding autoantigens and NAb binding KLH, except for IgG binding KLH and LYS, for which a low genetic correlation was found. Low to moderate phenotypic correlations were found between NAAb and NAb. In addition, significant maternal environmental effects of 0.03, 0.07, and 0.04 were observed for IgM binding OVA, LYS, and KLH, respectively. Results from this study indicated that NAAb or NAb levels in plasma were heritable and could provide tools to identify the health status of birds. [ABSTRACT FROM AUTHOR]

The combination of increased genetic potential and changes in management strategies (i.e., antibiotic-free, no antibiotics ever, and every day feeding of replacement pullets) influences the nutritional needs of poultry. Traditionally, nutritionists have focused on meeting the amino acid needs for production performance and yield however, increasing specific amino acid concentrations can benefit gastrointestinal development and integrity, enhance immune response potential, influence behavior, and benefit sustainability. Commercialization of additional feed grade amino acids beyond methionine, lysine, and threonine, enables targeted increases to achieve these benefits. As such, this paper addresses the functional roles of amino acids in meeting poultry production, health, and sustainability goals. [ABSTRACT FROM AUTHOR]

Poultry production is linked with the use of veterinary medicinal products to manage diseases. Ionophore coccidiostats have been permitted for use as feed additives within the European Union (EU) for the prevention of coccidiosis in various species of poultry with except of laying hens. The presence of chemical residues in eggs is a matter of major concern for consumers' health. Despite such prohibition of use in laying hens, they were identified as the most common non-target poultry species being frequently exposed to these class of coccidiostats. Many factors can influence the presence of residues in eggs. Carryover of these class of coccidiostat feed additives in the feed of laying hens has been identified as the main reason of their occurrence in commercial poultry eggs. The physicochemical properties of individual compounds, the physiology of the laying hen, and the biology of egg formation are believed to govern the residue transfer rate and its distribution between the egg white and yolk compartments. This paper reviews the causes of occurrence of residues of ionophore coccidiostats in eggs within the EU with special emphasis on their disposition kinetics in laying hens, and residue transfer into eggs. Additional effort was made to highlight future modeling perspectives on the potential application of pharmacokinetic modeling in predicting drug residue transfer and its concentration in eggs. [ABSTRACT FROM AUTHOR]

Providing environmental enrichments that increase environmental complexity can benefit poultry welfare. This Poultry Science Association symposium paper is structured around four themes on 1) poultry preferences and affective states 2) species-specific behavior, including play behavior and the relationship between behavior, activity level and walking ability, 3) environmental enrichment and its relationship with indicators of welfare, and 4) a case study focusing on the application of enrichments in commercial broiler chicken production. For effective enrichment strategies, the birds' perspective matters most, and we need to consider individual variation, social dynamics, and previous experience when assessing these strategies. Play behavior can be a valuable indicator of positive affect, and while we do not yet know how much play would be optimal, absence of play suggests a welfare deficit. Activity levels and behavior can be improved by environmental modifications and prior research has shown that the activity level of broilers can be increased, at least temporarily, by increasing the environmental complexity. However, more research on impacts of enrichments on birds' resilience, on birds in commercial conditions, and on slow(er)-growing strains is needed. Finally, incorporating farmers' expertise can greatly benefit enrichment design and implementation on commercial farms. [ABSTRACT FROM AUTHOR]

To have a better contribution to the poultry production community, the Poultry Science Association founded journals including Poultry Science (PS) at 1921. Now, after 100 yr of publishing, PS ranks between the top 10 journals in the category of "agriculture, dairy, and animal science". One hundred years after publishing the first paper in PS, the poultry industry has been completely revolutionized. Hence, it will be interesting to establish scientometrics study of the PS development during the last century. Therefore, based on findings of the current study, among countries/authors' collaborations, future research fronts, and possibility of hot topics in the coming years may be predictable. Accordingly, a total of 22,451 articles were retrieved. For content analyses, according to the PS categorization for subject areas, 14 different subject areas were developed, including "behavior, breeding and quantitative genetics, education and extension, health and welfare, immunology, management and environment, metabolism and nutrition, microbiology and virology, modeling, molecular biology, physiology and anatomy, production, products, processing and marketing, and reproduction". Considering the 100-yr of PS, the most frequent subject area was "nutrition and metabolism" (14,109 articles), and "modeling" (1,114 articles) attracted less scholarly attention. However, considering the last decade (2011–2020), the most important subject area was "molecular biology" (1,420 of 2,466 articles; 57.58%), followed by "modeling" (544 of 1,144 articles; 48.88%). Moreover, the most frequent poultry species/strains were broilers (retrieved in 6,156 articles), followed by laying hens, turkeys, and quail. Considering collaboration of countries and researchers, it can be said that a total number of 108 countries contributed to PS, with the most prolific country being United States (with 9,421 articles; 43.16%), followed by China, Canada, the Netherlands, and Japan. Among the authors, Harms RH (287 articles), and Siegel PB (208) were the most prolific authors, and Siegel PB and Dunnington EA (71 articles) had more collaborations. To study keyword trends, including 3 time periods broilers was the central co-occurrent keyword, while the importance of chickens and turkeys declined during the time. Salmonella spp. was a constant representative of poultry microbiology during 100 yr. While "nutrition and metabolism" was the most important subject area, nutrition-related keywords (major items) were not concentrated and co-occurred with a variety of keywords from different subject areas. While "molecular biology" ranked first over the past decade, the importance of "nutrition and metabolism" should not be ignored. In fact, in recent years, molecular basis of the nutrition has been studied. In big-data era and due to developing the molecular biology technologies, it seems that using mathematical modeling and computational methodologies will increase and probably remains as one of the most attractive research areas for scientists at least in the upcoming future decades. [ABSTRACT FROM AUTHOR]

The existing literature is inconsistent with respect to optimal dietary concentrations of glycine (Gly) and serine (Ser) in broiler feed. Therefore, we conducted a meta-analysis to investigate the response of broilers to dietary levels of Gly using a full quadratic model based on mixed model methodology. Response was measured as ADG (g/d), ADFI (g/d), and G:F (g/g). In addition, the influence of other dietary constituents was evaluated. This meta-analysis was based on a data set comprising a total of 9,626 broilers in 10 peer-reviewed papers that investigated the response of broilers to different dietary concentrations of Gly, achieved by addition of free Gly. The fitted quadratic model, with either Gly+Ser or the calculated glycine equivalent (Glyequi) of both amino acids as the independent variable, revealed that all model terms were significant (P ≤ 0.05), and hence proved a curvilinear relationship between these independent variables and response traits. The R² value and root MS error confirmed a strong relationship between observed and predicted traits. A comparison of the influence of Gly+Ser and Glyequi on response traits revealed that both approaches produced similar results. Because Glyequi should meet the physiological values of a diet better than Gly+Ser, models with 2 independent variables were conducted using Glyequi. The second independent variables were methionine (Met):TSAA ratio and the concentrations of cysteine (Cys) and CP. In models with one or 2 independent variables, the impact of dietary Gly on ADFI was low. By contrast, G:F was markedly influenced by dietary Gly; this effect intensified at lower Met:TSAA ratios and higher Cys and CP levels. ADG was also a function of Glyequi and the second independent variables. For ADG, an optimal Met:TSAA ratio of 0.655 and Cys concentration of 0.302% was calculated. Following the nonlinear nature of relationship, generally applicable replacement values could not be calculated. However, it was concluded that consideration of dietary Cys can diminish the requirement for Glyequi, and therefore, enable a reduction in the CP of broiler diets without limiting growth performance. [ABSTRACT FROM AUTHOR]

During the catching of broilers for slaughter, 2 to 3 birds are grabbed per hand at one leg at the same time. From an animal welfare point of view, this procedure is under critical observation from animal welfare administration and the general public. In this paper 2 catching methods were compared: the routinely used 1-leg catching method, and a second technique whereby birds were grabbed by both legs with a maximum of 2 birds per hand (2-leg catching method). Lesions on the body, legs, and wings (hemorrhages and fractures) were recorded by a camera system located after the plucking position. Two weight classes, 2 catching teams, and 2 flocks were included in the study. Heavy animals showed more lesions than birds of the light weight class. In all investigations, lesions on the body and legs were rare, whereas wing lesions occurred at a rate of up to 15.32%. Statistical analysis showed no significant difference between the 2 methods or between the catching teams for both weight classes. A correlation between lesions and weight was observed, with a significant odds ratio (OR) of 3.6 (95% CI: 3.299- 3.957). During 2-leg catching, the animals appeared to be more restless. Workers stated that the grabbing of both legs of a bird was more difficult and that working in a crouching position for a longer time was harder. We conclude that the cautious handling of animals to reduce stress is more important than "holding animals by both legs", as has been proposed. [ABSTRACT FROM AUTHOR]

Antimicrobial agents are added to poultry products after slaughter to prevent the growth of pathogenic and spoilage microorganisms and to extend the shelf-life of these products. Antimicrobials can be either natural or chemical, which may affect the sensory attributes at elevated concentrations, such as surface color, odor, flavor, taste, and texture of the poultry products. Thus, when selecting antimicrobials for use in poultry processing, it is vital to consider the antimicrobial-induced changes in sensory aspects from the consumers' perspectives. In spite of its importance, there has been no systematic review on the influences of antimicrobials on sensory aspects of poultry products. This paper reviews the major antimicrobial agents used in the poultry processing industry and their effects on sensory aspects of the poultry products. [ABSTRACT FROM AUTHOR]

Poultry and poultry meat are particularly susceptible to oxidative reactions. Oxidation processes have been for decades the focus of animal and meat scientists owing to the negative impact of these reactions on animal growth, performance, and food quality. Lipid oxidation has been recognized a major threat to the quality of processed poultry products. The recent discoveries on the occurrence of protein oxidation in muscle foods have increased the scientific and technological interest in a topic that broadens the horizons of food biochemistry into innovative fields. Furthermore, in recent years we have witnessed a growing interest in consumers on the impact of diet and oxidation on health and aging. Hence, the general description of oxidative reactions as harmful phenomena goes beyond the actual impact on animal production and food quality and reaches the potential influence of oxidized foods on consumer health. Likewise, the current antioxidant strategies aim for the protection of the living tissues, the food systems, and a potential health benefit in the consumer upon ingestion. Along these lines, the application of phytochemicals and other microelements (Se, Cu) with antioxidant potential in the feeds or directly in the meat product are strategies of substantial significance. The present paper reviews in a concise manner the most relevant and novel aspects of the mechanisms and consequences of oxidative reactions in poultry and poultry meat, and describes current antioxidant strategies against these undesirable reactions. [ABSTRACT FROM AUTHOR]

Traditionally, antibiotic growth promoters (AGP) have been used in foodstock animals to reduce enteric inflammation and maintain intestinal homeostasis, thus improving growth and performance. Due to increasing restrictions regarding the use of AGP however, precise and high throughput enteric inflammation models and markers to search for effective alternatives are urgently needed. In this paper, oral administration of fluorescein isothiocyanate dextran (FITCd, 3-5 kDa) and its passage into blood was used as a marker for tight junction permeability. In experiement 1, broilers were assigned to a control group, a group which received 24 h feed restriction (FR), or a group which received dextran sodium sulfate (DSS) (0.75% in water for 5 d), and each group then underwent an oral gavage of FITC-d 2.5 h before sample collection on d10. FITC-d in serum and intestinal samples (duodenum and ceca) were found to be higher (P < 0.05) after FR than in the DSS and control groups. In experiment 2, FR was evaluated for its effect on mucosal leakage and an oral dose of FITC-d of 0.5, 1.1, or 2.2 mg/chick was used to measure the gastrointestinal tract (GIT) permeability at 6 d of age. The amount of FITC-d remaining in the duodenal tissue of the control birds increased with dose, only the 1.1 mg FITCd/ chick dose resulted in differences (P < 0.05) between the control and FR groups. No differences were noted between the control and FR groups, regardless of FITCd dosage in cecal recovery of FITC-d. Additionally, FR increased FITC-d serum levels when compared to the control group and in a dose-dependent manner. Experiment 3 compared serum levels after administration of 0.55 and 1.1 mg/chick doses of FITC-d in birds treated with FR, rye-based diet (RBD), and DSS. Intestinal sections were collected for FITC-d recovery in the 1.1 mg dosage group. All inflammation treatments significantly increased serum FITC-d levels at both doses. Only FR resulted in increased (P < 0.05) FITC-d recovery from duodenum, ileum, and ceca. In conclusion, FR, DSS, and RBD affected GIT tight junction integrity, suggesting their value for enteric inflammation models, and FITC-d may be a good indicator of permeability. [ABSTRACT FROM AUTHOR]

Extensive research over the last couple of decades has made it obvious that mycotoxins are commonly prevalent in majority of feed ingredients. A worldwide mycotoxin survey in 2013 revealed 81% of around 3,000 grain and feed samples analyzed had at least 1 mycotoxin, which was higher than the 10- year average (from 2004 to 2013) of 76% in a total of 25,944 samples. The considerable increase in the number of positive samples in 2013 may be due to the improvements in detection methods and their sensitivity. The recently developed liquid chromatography coupled to (tandem) mass spectrometry allows the inclusion of a high number of analytes and is the most selective, sensitive, and accurate of all the mycotoxin analytical methods. Mycotoxins can affect the animals either individually or additively in the presence of more than 1 mycotoxin, and may affect various organs such as gastrointestinal tract, liver, and immune system, essentially resulting in reduced productivity of the birds and mortality in extreme cases. While the use of mycotoxin binding agents has been a commonly used counteracting strategy, considering the great diversity in the chemical structures of mycotoxins, it is very obvious that there is no single method that can be used to deactivate mycotoxins in feed. Therefore, different strategies have to be combined in order to specifically target individual mycotoxins without impacting the quality of feed. Enzymatic or microbial detoxification, referred to as "biotransformation" or "biodetoxification," utilizes microorganisms or purified enzymes thereof to catabolize the entire mycotoxin or transform or cleave it to less or non-toxic compounds. However, the awareness on the prevalence of mycotoxins, available modern techniques to analyze them, the effects of mycotoxicoses, and the recent developments in the ways to safely eliminate the mycotoxins from the feed are very minimal among the producers. This symposium review paper comprehensively discusses the above mentioned aspects. [ABSTRACT FROM AUTHOR]

A study with a 2 × 3 × 2 factorial arrangement was conducted to determine the effects of 2 dietary protein levels (high = CPh and low = CPl) during rearing, 3 dietary energy levels (3,000, MEh1; 2,800, MEs1; and 2,600, MEl1, kcal/kg AMEn, respectively) during the first phase of lay, and 2 dietary energy levels (2,800, MEs2; and 3,000, MEh2, kcal/kg AMEn, respectively) during the second phase of lay on body composition and reproduction in broiler breeders. No meaningful interactions for energy and protein treatments within the different phases of the study were found and, therefore, this paper focusses on the main effects. Pullets fed the CPl diet had a 12.8% higher feed intake, 14% lower breast muscle, and 97% higher abdominal fat pad portion at 22 wk age. The increased abdominal fat pad and decreased breast muscle of the CPl compared to the CPh birds increased hatchability during the first phase of lay, due to a decreased embryonic mortality between d 10 to 21 of incubation, and increased egg production during the second phase of lay. Feeding birds the MEh1 and MEl1 diets slightly decreased egg production compared to the MEs1 birds. Birds fed the MEh1 diet showed a higher mortality compared to the birds fed the MEs1 and MEl1 diets. Feeding birds the MEh2 diet did not affect egg production, increased hatchability of fertile eggs, decreased embryonic mortality between d 3 to 21 of incubation, and increased the number of first-grade chicks. It was concluded that a low-protein diet during rearing changed body composition with positive effects on incubation traits during the first phase of lay and improved egg production during the second phase of lay in broiler breeders. A high-energy or low-energy diet compared to a standard diet during the first phase of lay slightly decreased total and settable egg numbers while a high-energy diet during the second phase of lay increased hatchability and number of saleable chicks. [ABSTRACT FROM AUTHOR]

Natural antibodies (NAb) are an important component of the first line of immune defense. Selective breeding for enhanced NAb levels in chickens may improve general disease resistance. It is unknown what the consequences of selection for NAb will be on the productive performance of laying hens. In this paper we describe the genetic relations between NAb titers binding keyhole limpet hemocyanin at 19 wk age and production traits in a white purebred leghorn chicken line observed in several time periods. A linear animal model was used to estimate (co)variance components, heritabilities, and correlations. Negative genetic correlations were found between egg weight and NAb titers, and between egg breaking strength and NAb titers. Positive genetic correlations were found between the feed conversion ratio (consumed feed/egg mass produced) and NAb titers, and egg production and NAb titers. Negative phenotypic correlations were found between body weight and NAb titers, between egg weight and NAb titers, and between egg breaking strength and NAb titers. Positive phenotypic correlations were found between egg production and NAb titers, and feed conversion ratio and NAb titers. In general, phenotypic correlations were more often significant, but less pronounced than genetic correlations. Other production traits were not found to be significant related to NAb titers. These findings suggest that there is a genetic tradeoff between levels of immunity and some production traits, although the underlying mechanism(s) remain(s) unclear. The results suggest possible consequences for production efficiency as a result of selective breeding for improved general disease resistance by natural antibodies. [ABSTRACT FROM AUTHOR]

As for most vertebrates, reproduction in poultry is controlled by an integrated axis [the hypothalamo-pituitary-gonadal (HPG) axis]. External and internal cues are integrated at the level of the hypothalamus to initiate gonadal recruitment and control the subsequent reproductive cycle. Until recently, it was believed that the HPG was exclusively under stimulatory control from hypothalamic gonadotropin releasing hormone (GnRH). However in 2000, the discovery of gonadotropin inhibitory hormone (GnIH), an inhibitory peptide, changed this dogma. Since then, evidence accumulated to confirm that in fact the HPG is under a dual control system with a stimulatory and an inhibitory branch. In this paper, we review the organization of this dual control system, the mechanisms controlling the synthesis and release of GnRH and GnIH, and the possible integration and interactions between the two branches to regulate pituitary gonadotropes' function. Furthermore, as light perception and photoperiod are the primary cues utilized by the poultry industry in controlled environments, special consideration was given to potential practical applications. [ABSTRACT FROM AUTHOR]

Intensive genetic selection of broiler breeders and layer hens for economically important production traits, which has been carried out for almost a century, resulted in considerable differences in the mechanisms of growth and development and, thus, in avian metabolism, both during embryogenesis and after hatching. Selection for meat production (broiler breeders) and eggs (layer hens) led to increased productivity but also brought about metabolic disorders. That intensive genetic selection of broiler breeders and layer hens is effective is seen, for example, in the differences in growth and development, metabolism of the yolk sac, hormones and lipids, gas exchange, and thermogenesis. Due to genetic proximity and different developmental mechanisms in broiler breeders and layer hens, avian embryos and chicks serve as excellent models for fundamental scientific research. This review paper discusses the consequences of different growth rates as a result of long-term genetic selection on embryonic development and metabolic rate of broilers and layers. The evidence presented herein indicates that it would be worth comparing these issues in a meta-analysis. [ABSTRACT FROM AUTHOR]

Chronic heat is a major stress factor in laying hens and many studies on the effect of heat stress have been published. It remains difficult, however, to draw general conclusions about the effect of chronic heat stress on performance and its relationship with genetic and environmental factors, as these studies have been done under varying experimental conditions and using various experimental designs. A metaanalysis enabled us to make a quantitative review of the results from 131 published papers. The relative effects of four factors (genotype, age, group size, and amplitude of temperature variation) and their interactions with temperature were analyzed for 13 traits. After pre-correcting the data for a random study effect, the best model for each trait was selected in a stepwise procedure based on its residual sum of squares. Shell strength, daily feed intake, egg mass, and henday egg production were found to be more sensitive to heat stress than the other traits as they dropped by 9.0 to 22.6% between thermo-neutrality (15 to 20°C) and heat stress (30 to 35°C) while yolk and albumen proportions or Haugh units showed nearly no variation with temperature (<1.2% between thermo-neutrality and heat stress). Many interactions (17) were found between temperature and one or more factors in the 13 traits studied here, which reinforces the interest of using a meta-analysis to summarize data from the literature. This study highlighted that the impact of heat stress in laying hens depends on the genotype, age, and group size, some of which have rarely been investigated. [ABSTRACT FROM AUTHOR]

To comprehensively assess conventional vs. some alternative laying-hen housing systems under U.S. production conditions, a multi-institute and multi-disciplinary project, known as the Coalition for Sustainable Egg Supply (CSES) study, was carried out at a commercial egg production farm in the Midwestern United States over two single-cycle production flocks. The housing systems studied include a conventional cage house (200,000 hen capacity), an aviary house (50,000 hen capacity), and an enriched colony house (50,000 hen capacity). As an integral part of the CSES project, continual environmental monitoring over a 27-month period described in this paper quantifies indoor gaseous and particulate matter concentrations, thermal environment, and building ventilation rate of each house. Results showed that similar indoor thermal environments in all three houses were maintained through ventilation management and environmental control. Gaseous and particulate matter concentrations of the enriched colony house were comparable with those of the conventional cage house. In comparison, the aviary house had poorer indoor air quality, especially in wintertime, resulting from the presence of floor litter (higher ammonia levels) and hens’ activities (higher particulate matter levels) in it. Specifically, daily mean indoor ammonia concentrations had the 95% confidence interval values of 3.8 to 4.2 (overall mean of 4.0) ppm for the conventional cage house; 6.2 to 7.2 (overall mean of 6.7) ppm for the aviary house; and 2.7 to 3.0 (overall mean of 2.8) ppm for the enriched colony house. The 95% confidence interval (overall mean) values of daily mean indoor carbon dioxide concentrations were 1997 to 2170 (2083) ppm for the conventional cage house, 2367 to 2582 (2475) ppm for the aviary house, and 2124 to 2309 (2216) ppm for the enriched colony house. Daily mean indoor methane concentrations were similar for all three houses, with 95% confidence interval values of 11.1 to 11.9 (overall mean of 11.5) ppm. The 95% confidence interval values (overall mean) of daily mean PM10 and PM2.5 concentrations, in mg/m3, were, respectively, 0.57 to 0.61 (0.59) and 0.033 to 0.037 (0.035) for the conventional cage house, 3.61 to 4.29 (3.95) and 0.374 to 0.446 (0.410) for the aviary house, and 0.42 to 0.46 (0.44) and 0.054 to 0.059 (0.056) for the enriched colony house. Investigation of mitigation practices to improve indoor air quality of the litter-floor aviary housing system is warranted. [ABSTRACT FROM PUBLISHER]

The recent multistate outbreak of a multidrug-resistant (MDR) Salmonella Heidelberg strain from commercial poultry production highlights the need to better understand the reservoirs of these zoonotic pathogens within the commercial poultry production and processing environment. As part of a larger study looking at temporal changes in microbial communities within the major water tanks within a commercial processing facility, this paper identifies and characterizes Salmonella enterica isolated from the water in a final scalder tank at 3 times during a typical processing day: prior to the birds entering the tank (start), halfway through the processing day (mid), and after the final birds were scalded (end). Over 3 consecutive processing days, no Salmonella were recovered from start-of-day water samples, while a total of 56 Salmonella isolates were recovered from the mid-day and end-of-day scalder water samples. Traditional and newer PCR-based serotyping methods eventually identified these isolates as either group C3 S. Kentucky (n = 45) and group B S. Heidelberg (n = 11). While none of the S. Kentucky isolates possessed any resistances to the antimicrobials tested, all S. Heidelberg isolates were found to be multidrug resistant to 5 specific antimicrobials representing 3 antimicrobial classes. Due to the potential public health impact of S. Heidelberg and the recent nationwide poultry-associated outbreak of multidrug-resistant S. Heidelberg, future studies should focus on understanding the transmission and environmental growth dynamics of this serotype within the commercial poultry processing plant environment. [ABSTRACT FROM PUBLISHER]

The intestinal microbiota has attracted tremendous attention in the field of the poultry industry due to its critical role in the modulation of nutrient utilization, immune system, and consequently the improvement of the host health and production performance. Accumulating evidence implies intestinal microbiota of laying hens is a potential mediator to improve the prevalent issues in terms of egg quality decline in the late phase of laying production. However, the regulatory effect of intestinal microbiota on egg quality in laying hens remains elusive, which requires consideration of microbial baseline composition and succession during their long lifespans. Notable, although Firmicutes, Bacteroidetes, and Proteobacteria form the vast majority of intestinal microbiota in layer hens, dynamic intestinal microbiota succession occurs throughout all laying periods. In addition to the direct effects on egg safety, intestinal microbiota and its metabolites such as short-chain fatty acids, bile acids, and tryptophan derivatives, are suggested to indirectly modulate egg quality through the microbiota-gut-liver/brain-reproductive tract axis. These findings can extend our understanding of the crosstalk between intestinal microbiota and the host to improve egg quality and safety. This paper reviews the compositions of intestinal microbiota in different physiological stages of laying hens and their effects on egg quality and proposes that intestinal microbiota may become a potential target for modulating egg quality and safety by nutritional strategies in the future. [ABSTRACT FROM AUTHOR]

In this paper, the physicochemical and nutritional characteristics of preserved duck egg white were analyzed and compared with fresh egg and hardcooked egg white (n = 3). The data obtained showed that the preserved egg white was rich in essential amino acids and minerals, such as Ca, Mg, Fe, Zn, Cu, K, and Na. After fresh duck eggs were processed into preserved eggs, contents of moisture, CP, amino acid, and watersoluble vitamin of egg white significantly decreased (P < 0.05); however, pH, free amino acid content, and most inorganic elemental contents of egg white significantly increased (P < 0.05). The preserved egg white had higher a* (redness/greenness) and b* values (yellowness/ blueness; P < 0.05) and lower L* value (lightness; P < 0.05) than hard-cooked egg white. The gel hardness of preserved egg white was approximately 50% of hard-cooked egg white; however, its springiness and cohesiveness were approximately 1.5 times of hard-cooked egg white. The results indicated that pickling with alkaline and other additives can significantly change physical properties and chemical composition of duck egg white, which make preserved egg white with characteristics of rich elements, brown color, and high springiness, but low vitamin. [ABSTRACT FROM AUTHOR]

Increased mobility of hens in noncaged housing presents possibilities for bone breakage due to crash landings from jumps or flights between perches or housing infrastructure. Because bone breakage is a welfare and economic concern, understanding how movement from different heights affects hen landing impact is important. By tracking 3-dimensional bird movement, an automated sensor technology could facil-itate understanding regarding the interaction between noncage laying hens and their housing. A method for detecting jumps and flight trajectories could help ex-plain how jumps from different heights affect hen land-ing impact. In this study, a wearable sensor-based jump detection mechanism for egg-laying hens was designed and implemented. Hens were fitted with a lightweight (10 g) wireless body-mounted sensor to remotely sam-ple accelerometer data. Postprocessed data could de-tect occurrence of jumps from a perch to the ground, time of jump initiation, time of landing, and force of landing. Additionally, the developed technology could estimate the approximate height of the jump. Hens jumping from heights of 41 and 61 cm were found to land with an average force of 81.0 ± 2.7 N and 106.9 ± 2.6 N, respectively, assuming zero initial velocity (P < 0.001). This paper establishes the technological fea-sibility of using body-mounted sensor technology for jump detection by hens in different noncage housing configurations.. [ABSTRACT FROM AUTHOR]

Egg whites can undergo gelation at extreme pH. In this paper, the effects of NaOH concentration (1.5, 2, 2.5, and 3%), temperature (10, 20, 30, and 40°C), and additives (metallic compounds, carbohydrates, stabilizers, and coagulants) on the strength of alkaline-induced egg white gel were investigated. Results showed that NaOH concentration and induced temperature significantly affected the rate of formation and peak strength of the egg white gel. Of the 6 metallic compounds used in this experiment, CUSO4 exhibited the optimal effect on the strength of alkalineinduced egg white gel, followed by MgCl2, ZnSO4, PbO, and CaCl2- When CUSO4 concentration was 0.2%, the gel strength increased by 31.92%. The effect of Fe2(SO4)3 was negligible. Of the 5 carbohydrate additives, xanthan gum (0.2%) caused the highest increase (54.31%) in the strength of alkaline-induced egg white gel, followed by sodium alginate, glucose, starch, and sucrose. Meanwhile, propylene glycol (0.25%) caused the highest improvement (15.78%) in the strength of alkaline-induced egg white gel among the 3 stabilizing agents and coagulants used, followed by Na2HPO4 and glucono-δ-lactone. [ABSTRACT FROM AUTHOR]

Since it started as an organized economic activity, poultry production has been undergoing an evolution toward the optimization of its feed formulation features. Notably, advances in the knowledge of birds' nutrient requirements have allowed recommendations that are increasingly closer to the needs of the birds. Over time, availability of nutrients and energy has been incorporated into those recommendations, especially to compensate for the variability in the digestibility of nutrients originating from variable feed ingredient sources. Instead of using the total energy and nutrient content, current tables of nutrient recommendations provide an estimate of the digestible fractions of the nutrients in ingredients. For instance, nonphytate P is preferred instead of total P to account for the unavailable phytate P, and digestible amino acids to account for the differences in digestibility of amino acids in different ingredients, whereas energy is usually expressed as a proportion that has been digested and metabolized (AME). With the increasing interest in the use of exogenous enzymes in poultry feeds, special attention is directed to the feed substrates such that an added enzyme can match it, forming an enzyme-substrate complex that will be followed by a chemical reaction within the gastrointestinal tract. As a consequence of a degradation reaction, nutrients released can be absorbed and metabolized. In general, nutritional data banks used in linear feed formulation software have limited data on the proportions of fractions of ingredients that are indigestible. Therefore, estimations of the presence of many substrates in the feeds, and therefore the benefits of adding exogenous enzymes, are frequently limited because of the scarcity of adequate information. The objective of this review paper is to provide insights into the use of expanded nutrient databanks to include all the molecules considered potentially indigestible for poultry such that the inclusion of exogenous enzymes allows the estimation of the values of the product originated by their hydrolysis. [ABSTRACT FROM AUTHOR]

The current paper reviews content and variation in fiber and nonstarch polysaccharides (NSP) of common crops used in broiler diets. The cereal grain is a complex structure, and its cell walls (CW) differ in their composition and hence properties. Arabinoxylan (AX), mixed linkage (1-->3; 1-->4)-(βglucan (βglucan), cellulose, and the noncarbohydrate component lignin are the predominant polymers in cereals. They occur in different proportions depending on the species and tissue type. Rye, triticale, wheat, corn, and sorghum are all rich in AX, whereas barley and oats contain a high level of (βglucan. The AX from rye, wheat, and triticale and (βglucan from barley and oats are to a large extent soluble, whereas the solubility of AX found in corn and sorghum is lower than the other cereals. The ratio of arabinose to xylose gives a crude indication of the AX structure, which varies between the endosperm, the aleurone and the outer grain layers as well as between the same tissues from different grains. Varietal differences in AX structure of the endosperm are also identified. From the analysis of the released oligomers after hydrolysis with a specific (1-->3,l-->4)-(β-D-glucan hydrolase, it is found that the ratio of trisaccharides (degree of polymerization 3) and tetrasaccharides (degree of polymerization 4) varies depending on the source, being higher in barley than in oats but lower than in wheat. The molecular weight of (3-glucan is higher than that of AX, and both polymers contribute to the viscosity of the extract. However, because AX molecules are more resistant to degradation than (β-glucan, the use of AX rich grains in broiler diets is usually more problematic than those containing high concentrations of (β-glucan. The cereal coproducts (brans and hulls) are concentrated sources of cellulose, lignin, and insoluble AX, but (β-glucan can also be present mainly in rye and wheat brans. The CW composition of seeds and grains of protein crops and feedstuffs are different from that of cereals. The main CW polymers are pectic substances (homogalacturonan, rhamnogalacturonan type I and II, xylogalacturonan, and arabinogalactans type I and II), xyloglucans, and cellulose, but there are significant differences in the composition of the parenchymatous (cotyledon) tissues and that of the hulls. In the hulls, cellulose is the predominant polysaccharide, followed by acidic xylans and pectic substances. The implications of the heterogeneous CW for the action of exogenous enzymes are discussed. [ABSTRACT FROM AUTHOR]

Interleukin-1β proteins from chicken, duck, goose, turkey, and pigeon share 77 to 99% amino acid sequence similarity among themselves, and only 31 to 35% sequence similarity is shared between avian and mammalian IL-1(3. There have been no antibodies that specifically detect avian IL-1β, and the current study was conducted to develop mouse monoclonal antibodies (mAb) against chicken IL-1β (chIL-lβ to further define its biochemical and immunological properties. In this study, 2 mouse mAb that are specific for chIL-1β were produced and characterized. Both mAb identified a 66.0 kDa recombinant chIL-lβ protein expressed in Escherichia coli by Western blot analysis that corre sponded to the expected molecular weight of a recombinant fusion protein containing the full-length 23.0 kDa chIL-lβ protein and a 43.0 kDa maltose binding protein tag. Immunohistochemical analysis identified cells producing endogenous chIL-lβ in the cecal tonsils, bursa of Fabricius, and spleen. Purified recombinant chlL-lp dose-dependently stimulated the proliferation and nitric oxide production by thymocytes, and both activities were inhibited by co-incubation with the 2 cliIL-lβ mAb described in this paper. These mAb will be important immune reagents for basic and applied poultry research of IL-1β in poultry [ABSTRACT FROM AUTHOR]

This study estimated the genetic vari-ance components of P utilization in Japanese quail. A parental generation was assembled from an unselected random-bred Japanese fattening quail line. Seven sires and 14 dams were randomly selected, and each sire was paired with 2 dams to produce full and half sibs. A total of 200 unsexed 1-d-old quail with known pedigree were wing-banded and raised during the first 4 d post-hatch in groups in floor pens on wood shavings and fed a preexperimental diet that was adequate in all nutri-ents. Starting on d 5, quail were individually housed in metabolic compartments on P-free filter paper. This started a balance trial with 5 d of adaption and 5 d of total excreta collection. During this balance period, all quail were fed a low-P (3.9 g/kg of DM) corn-soybean meal-based diet with a Ca:P ratio of 1.6:1.0. Phospho-rus and Ca utilization were determined individually us-ing the difference in P or Ca intake and the total P or Ca excretion. The average P utilization was 72% and the average Ca utilization was 63%, each with very high variation. Heritabilities were estimated to be 0.09 (SE = 0.09) for P utilization and 0.09 (SE = 0.09) for Ca utilization. Heritabilities were close to the values reported in the literature for broilers and suggest that quail are suitable as a model animal. The SE of the her-itability estimates were large. This implies that further studies with a larger sample size are needed to identify genetic and physiological mechanisms that influence P and Ca utilization in Japanese quail. [ABSTRACT FROM AUTHOR]

Previous results suggested that the gastric function plays a paramount role in digestive efficiency differences between D+ and D- broiler lines divergently selected for AMEn (more feed efficient and less feed efficient, respectively). In this paper we show an histological analysis of the gastric isthmus located between the proventriculus and the gizzard in the D+ and D -lines. Cross-sections were performed using a cryostat (Leica CM30505) and stained with a routine procedure using Mayer's Hematoxylin and Eosin Stain. The surface and shape of the constitutive gastric isthmus tissues were quantified using the image analysis software Image J. The lumen occupied 11% of the whole D -isthmus cross-sectional area against 24% for D+ (P < 0.01). The mucosa relative area (cm2/total cross-sectional area) was higher in D- than in D+ [47% (D-) and 39% (D+), P < 0.01]. It was significantly more oval and more folded on the lumen side in D- than in D+ chickens; the muscle layer (muscularis mucosae) of the mucosa was relatively more developed in D- than in D+ (16 and 11% of the section, respectively; P < 0.01). A relationship between these observations and increased gastric motility reported in D- compared with D+ is discussed. [ABSTRACT FROM AUTHOR]

The growth performance and health of chicks can be significantly improved by a suitable microclimate in brooder houses. However, the microclimate of the chicken house is affected by factors such as its structure and the heat dissipation of chickens, making it is difficult to establish an accurate mathematical model and achieve effective regulation. In this paper, the environmental data acquisition system of enclosed chick brooder house was established by analyzing various environmental factors in brooder houses. According to the structural characteristics of brooder houses and the growth environment of chicks and other parameters, the microclimate simulation model of brooder houses was established using the physical law of energy balance. The coefficient of determination R2 (R-square) between simulated temperature and humidity output value and measured value was 0.7634 and 0.9740, respectively, and Root Mean Square Error (RMSE) was 1.55°C and 2.61%, respectively. The correctness of the simulation model was verified. On the basis of established microclimate models, a simulation model of fuzzy decoupling Proportion Integration Differentiation (PID) control in chicken house environments was established for the strong coupling between temperature control and general risk control system in chicken houses. Different control strategies were generated by fuzzy and logical reasoning about multiple environmental factors. The compensation coefficient was added to optimize the environmental regulation system of brooder houses. The temperature maximum deviation between the set value and the fuzzy decoupling PID controller was 0.5°C, the maximum relative error was 2.7%, the maximum deviation of relative humidity between the set value and the fuzzy decoupling PID controller was 4.93%, the maximum relative error was 10.49%.The simulation results show the control strategy meets the temperature and humidity control requirements, verify the effectiveness of the control strategy and model. The experimental results can guide the actual environmental control of brooder houses. [ABSTRACT FROM AUTHOR]

The paper aimed to study the effects of light regime on circadian rhythmic behavior and reproductive parameters in a native laying hen, Beijing You Chicken (BYC) during 22 to 30 wk. A total of 630 19-wk-old BYC female chicken were allocated to 6 light regime groups with 3 replicates per group and 35 birds per replicate, reared in individually lit floor pens with separate outdoor areas. A 2 × 3 factorial experiment (2 lighting patterns: continuous and intermittent lighting; 3 photoperiods: 16 h, 14 h, 12 h) was arranged, including 16L:8D for group 1; 12L:2D:4L:6D for group 2; 14L:10D for group 3; 10L:2D:4L:8D for group 4; 12L:12D for group 5, and 8L:4D:4L:8D for group 6, respectively. The circadian rhythmic behavior of the hens, including feeding, egg-laying and sleeping behaviors were observed by scan sampling and target sampling method for consecutive 3 d every other week during 22 to 30 wk. Infrared cameras were set outside each pen to record the rhythmic behaviors of the birds every other hour (6:00–7:00;8:00–9:00;10:00–11:00;12:00–13:00;14:00–15:00;16:00–17:00;18:00–19:00;20:00–21:00;22:00–23:00;0:00–1:00;2:00–3:00;4:00–5:00). Theovarian weight, oviduct weight, oviduct length, the number of large yellow follicles (LYF), and small yellow follicles (SYF) were measured at the end of 30 wk. The egg-laying rate during 22 to 30 wk was measured. The results showed that the highest feeding frequency was given by the 16L:8D, and the lowest given by the 12L:12D (P < 0.05). The average feeding duration was the longest in the 8L:4D:4L:8D at 6:00 to 8:00 (18.67 min/hen) (P < 0.05), and the shortest in the 8L:4D:4L:8D at 18:00 to 20:00 (3.75 min/hen) (P < 0.05). The highest egg-laying frequency was given by the 8L:4D:4L:8D (0.28), the lowest given by the 10L:2D:4L:8D (0.21) (P < 0.05). The shortest egg-laying duration occurred at 6:00 to 8:00, was given by the 16L:8D (8 min/hen), and the longest egg-laying duration occurred at 18:00 to 20:00, was given by 16L:8D and 8L:4D:4L:8D (>20.5 min/hen) (P < 0.05). The highest sleeping frequency was given by the 12L:2D:4L:6D, the lowest was given by the 12L:12D (P < 0.05). At 6:00 to 8:00, the shortest sleeping duration was given by 12L:2D:4L:6D (1.5 s/hen), at 18:00 to 20:00, the longest given by 8L:4D:4L:8D (14.3 s/hen) (P < 0.05). Lighting pattern and photoperiod alone or in interaction had no effect on egg-laying rate during 22 to 30 wk (P > 0.05), but had significant effects on ovarian weight, oviduct weight, oviduct length, the number of LYF and SYF (P < 0.05), and the continuous groups were all significantly higher than the intermittent groups (P < 0.05). The present study indicated that light regimes affected the frequency and duration of circadian behavior in BYC laying hens, and the continuous light was more beneficial to the reproductive development than the intermittent light in the early laying period. [ABSTRACT FROM AUTHOR]

The effects of heating of eggs during stor-age, broiler breeder age, and length of egg storage on hatchability of fertile eggs were examined in this study. Eggs were collected from Ross 344 male x Ross 308 broiler breeders on paper flats, held overnight (1 d) at 18°C and 75% RH, and then transferred to plastic trays. In experiment 1, eggs were obtained at 28, 38, and 53 wk of flock age. During a further 10 d of stor-age, eggs either remained in the storage room (control) or were subjected to a heat treatment regimen of 26°C for 2 h, 37.8°C for 3 h, and 26°C for 2 h in a setter at d 5 of storage. In experiment 2, eggs from a flock at 28 wk of age were heated for 1 d of a 6-d storage period. Eggs from a 29-wk-old flock were either heated at d 1 or 5 of an 11-d storage period in experiment 3. In ex-periment 4, 27-wk-old flock eggs were heated twice at d 1 and 5 of an 11-d storage period. Control eggs stored for 6 or 11 d were coincubated as appropriate in each experiment. Heating eggs at d 5 of an 11-d storage pe-riod increased hatchability in experiment 1. Although no benefit of heating 28-wk-old flock eggs during 6 d of storage in experiment 2 was observed, heating eggs from a 29-wk-old flock at d 1 or 5 of an 11-d storage period increased hatchability in experiment 3. Further, heating eggs from a 27-wk-old flock twice during 11 d of storage increased hatchability in experiment 4. These effects were probably due to the fact that eggs from younger flocks had been reported to have many embry-os at a stage of development where the hypoblast had not yet fully developed (less than EG-K12 to EG-K13), such that heating during extended storage advanced these embryos to a more resistant stage. [ABSTRACT FROM AUTHOR]

Transgenerational epigenetics is becoming more and more important for understanding the variation of physiological responses of individuals to the environment and the inheritance of these responses based on all mechanisms other than the actual DNA nucleotide sequence. Transgenerational epigenetics is the phenomenon that the information of the environment of (usually) a female animal is translated into memory-like responses preparing the offspring. As a consequence, individuals of the next generation may show different phenotypic traits depending whether their mothers were kept under different environmental conditions. This may result in either positive or negative effects on the next-generation individuals, which is different from individuals from mothers that have been kept in a different environment. Transgenerational epigenetic effects have been proposed and indicated for specific immune (T cell and antibody) responses (especially in mammals, but also in birds) and innate immunity (nonvertebrates), but surprisingly very little is known of transgenerational effects on innate immunity in chickens. Given the short lifespan of the chicken and therefore the likely dependence of chicken on innate immune mechanisms, more attention should be given to this arm of immunity and mechanisms of inheritance including transgenerational effects that can be initiated in the breeder generation. In addition, it is becoming evident that innate immunity also underlies metabolic disorders in broilers. In the current paper, we will argue that although very little is known of transgenerational effects of innate immunity in poultry, more attention should be given to this type of study. We will illustrate examples of transgenerational epigeneties, and finally propose strategies that should reveal the presence of transgenerational epigenetic effects on innate immunity in chickens and strategies to modulate breeder birds such that these effects positively affect innate immunity of broilers. It is suggested that a mismatch between breeder environment and broiler environment may account for unwanted effects of innate immunity in the broiler. [ABSTRACT FROM AUTHOR]

A given data set can be analyzed many ways, but only one is the correct analysis based on the design actually used when running the experiment. This work gives a tutorial-like illustration of the effects of the presence of a regression variable (or covariate) on the recorded responses in an experiment set up as a standard factorial design and shows how the analysis results are to be adjusted for the presence of covariates. An underlying assumption of a factorial model is that each of the treatments (e.g., diets) is randomly allocated to different subjects (hens). When many measurements (e.g., over time) are made on the same subject (hen), this independence assumption is violated; in these cases, the design is an example from the class of repeated measures designs. The difference in analysis between factorial designs and repeated measures designs is also discussed. Then, the 2 concepts are merged wherein the results for a repeated measures analysis have to be adjusted for the presence of covariates. The paper concludes with analyses on the results of egg production responses from an experiment in which repeated measurements were made on the same hens and in which an unanticipated temperature covariate was present. [ABSTRACT FROM AUTHOR]

Different packaging is available to consumers, and marination is widely applied. However, their effects on the quality of broiler breast fillets during home freezing are not well known to consumers. Therefore, the objective of this study was to evaluate the effect of packaging materials on the quality of chicken breast fillets after 1, 3, and 6 wk storage at -- 18°C. A total of 256 fillet were randomly placed in tray packs, freezer bags, butcher paper, and nonpackaged controls. Samples were analyzed for raw pH, color, percent moisture content, and TBA reactive substances (TBARS) at d 0 (only nonpackaged controls), wk 1, 3, and 6, and cooked texture and sensory attributes at wk 1 and 6. There were differences (P < 0.05) in pH, color, percent moisture content, and texture among the treatments by wk 6, but no differences (P < 0.05) in TBARS values and the sensory evaluation (tenderness, juiciness, and overall flavor) were seen. Consumers were not able to detect quality differences (P < 0.05) among treatments despite analytical differences. Experiment 2 was conducted to evaluate the effects of marination on the quality of chicken breast fillets after 2 wk of storage in a home freezer (--18°C). A total of 240 fillets were used in the treatments: nonmarinated fresh nonfrozen, nonmarinated frozen, marinated fresh nonfrozen, and marinated frozen. Fillets were vacuum-tumbled in a 10% solution yielding a final concentration of 0.45% sodium tripolyphosphate and 0.65% salt in the meat. Raw samples were evaluated for color, TBARS, and thaw loss. Cooked samples after 2 wk of storage were analyzed for cook loss, texture, moisture, and sensory evaluation (color, juiciness, tenderness, overall flavor, and preference). Both marinated samples showed better (P < 0.05) quality in terms of L* value, TBARS, cook loss, texture, moisture content, and better sensory attributes (except color) than nonmarinated samples. Quality of marinated samples was not negatively affected by home freezing after 2 wk. [ABSTRACT FROM AUTHOR]

Hypoxia-inducible factor 1 (HIF-1) is a ubiquitously expressed heterodimeric transcription fac-tor that mediates adaptive responses to hypoxia in all nucleated cells of metazoan organisms. Hypoxia-induc-ible factor la is involved in the pathogenesis of pulmo-nary hypertension in humans and animals, but whether HIF-la is associated with the development of pulmo-nary hypertension syndrome (also known as ascites syndrome, AS) in broiler chickens has not been deter-mined. In the present paper we addressed this issue by measuring the expression of HIF-la mRNA in hearts and lungs of broiler chickens with AS induced by excess salt in drinking water. We conducted 2 experiments. The first experiment was used to observe the effects of excess salt on AS incidence. The results indicated that total incidence (20%) of AS in excess salt group (re-ceiving 0.3% NaCl in drinking water) was much higher compared with the control group (receiving tap water) over a 43-d time course (P < 0.05). In the second experi-ment, we determined mean pulmonary arterial pressure (mPAP), ascites heart index (AHI), and expression of HIF-la mRNA in lungs and hearts of broiler chickens after the excess salt treatment. Our results showed that excess salt induced pulmonary hypertension (indicated by higher mPAP) and right ventricular hypertrophy (greater ascites heart index) in broiler chickens. Mean-while, the expression levels of HIF-la mRNA in lungs and hearts were significantly increased at different time points in the excess salt group compared with the con-trol group. Linear correlation analysis showed that the expression of HIF-la mRNA in lungs was significantly positively correlated with mPAP (correlation coeffi-cient -- 0.79, P < 0.001), demonstrating that expres-sion of HIF-la mRNA was gradually increased in the excess salt group with the increase of pulmonary arte-rial pressure. In addition, the ascitic chickens showed significantly higher transcriptional levels of HIF-la in hearts and lungs, compared with the age-matched healthy chickens, respectively Our findings hinted that HIF-la might be associated with the development of AS induced by excess salt in drinking water in broiler chickens. [ABSTRACT FROM AUTHOR]

In the United States, empirical information on the sustainability of commercial-scale egg production is lacking. The passage of state regulations specific to hen housing created urgency to better understand the effects of different housing systems on the sustainability of the egg supply, and stimulated the formation of a coalition, the Coalition for a Sustainable Egg Supply (CSES), to conduct research on this topic. The CSES is a multi-stakeholder group with 27 members, including food manufacturers, research institutions, scientists, restaurants, food service, retail food companies, egg suppliers, and nongovernmental organizations. A commercial-scale study was developed to better understand the effect of 3 housing systems (conventional cage, enriched colony, and cage-free aviary) on 5 areas related to a sustainable egg supply. These 5 sustainability areas represent effects on people, animals, and the environment: animal health and well-being, environment, food safety, worker health and safety, and food affordability. Five teams of scientists, each associated with a sustainability area, conducted an integrated field study at a commercial site in the upper Midwest through 2 flock cycles in 3 housing systems. This paper provides a brief overview of the CSES project to serve as an introduction for the papers that follow in this volume of Poultry Science. [ABSTRACT FROM PUBLISHER]

Persons conducting research trials often want to be able to declare that treatments, or particularly products, are equivalent (will provide indistinguishable results). However, all research trials can ever provide is the probability that the observed differences in an experiment were due to chance. Also, in trials in which variances are high and there are few replications, it is quite easy to declare no significant differences and equivalency. This paper describes a Microsoft Excel spreadsheet that can be used to easily construct experimental power curves. Such curves predict the proportion of experiments that would yield a given level of significance as the difference between the 2 means increases. The spreadsheet uses the mean and variances from an experiment with the Norm.inv and Rand functions of Excel to simulate outcomes from identical experiments. An experiment that declared GMO and normal feed ingredients to be equivalent was used to illustrate the application of power curves. The experiment had 12 replicate pens of broilers per treatment. The outcomes of 90,000 simulated experiments, each with the same overall variance, but 0 through 8 percent differences in treatment means, were graphed. When the published experiment purported to show equivalence, really it showed that a significant difference in growth (P < 0.05) would be expected to be detected 50% of the time if the means were different by 3.1%; a difference of 4.6% in treatment means could be detected 80% of the time by such an experiment. This Excel spreadsheet enables such a power analysis to be conducted. Easy modifications of the spreadsheet can illustrate the influence of changing the variance or number of replications on the expected power of future experiments. The economic impact of small changes in performance is also discussed. [ABSTRACT FROM AUTHOR]

Reducing the level of nonphytate P (NPP) in diets for laying hens without negatively af-fecting their productivity and heath is crucial for sus-tainable egg production. A meta-analytical approach using a full quadratic model was applied to quantify relationships between dietary NPP and phytase levels and performance of laying hens. Egg production (EP, %), egg mass (EM, g/hen/day), and feed conversion ratio (FCR) were considered as model outputs. A data set containing 168 P or P plus phytase treatments was extracted from 12 published papers. The data were as-sembled from 14 trials with a total of 8,752 hens in the range of 36 to 76 wk of age. The EP, EM, and FCR were analyzed using a linear mixed model that included the linear and quadratic effects of dietary NPP and phytase levels and their interactions. Except for the quadratic effect of dietary phytase on FCR, all other model components (that is, intercept, linear, quadratic, and interactions) were significant (P < 0.05). There was a relatively strong relationship between observed and predicted EP (R2 = 0.78, RMSE = 3.73), EM (R2 = 0.84, RMSE = 2.09), and FCR (R2 = 0.78, RMSE = 0.11), demonstrating that observations within study are practically predictable. Analyses of the model re-vealed that corn-soybean meal-based diets containing 0.22% of NPP without supplemental phytase resulted in high EP, EM, and feed efficiency in layers. In the presence of 150, 300, and 400 phytase units (FTU)/kg of feed, the dietary NPP level may be decreased and optimal levels were calculated as 0.18, 0.15, and 0.14%, respectively. [ABSTRACT FROM AUTHOR]

Following is invited commentary on the symposium "A Crystal Ball Look into the Future of..." delivered July 16, 2011, at the Poultry Science Association's 100th annual meeting, St. Louis, Missouri. The symposium examined various aspects that will impact the future of poultry production over the next 10 to 20 years. Topics included genetics, nutrition, incubation, and bird health. This paper deals with various aspects of future issues affecting global feeding and nutrition of poultry. [ABSTRACT FROM AUTHOR]

Following is invited commentary on the symposium "A Crystal Ball Look into the Future of..." delivered July 16, 2011, at the Poultry Science Association's 100th annual meeting, St. Louis, Missouri. The symposium examined various aspects that will impact the future of poultry production over the next 10 to 20 yr. Topics included genetics, nutrition, incubation, and bird health. This paper deals with various aspects of future issues affecting global feeding and nutrition of poultry. [ABSTRACT FROM AUTHOR]

The effects of postdeboning aging and frozen storage on water-holding capacity (WHC) of chicken breast pectoralis major muscle were investigated. Broiler breast muscle was removed from carcasses either early postmortem (2 h) or later postmortem (24 h). Treatments included: no postdeboning aging; 1-d postdeboning aging at 2°C, 7-d postdeboning aging (2-h deboned meat only), and 6-d storage at -20°C plus 1-d thawing at 2°C (freezing and thawing treatment, 2-h deboned meat only). The WHC was determined by cooking loss, drip loss, a filter paper press method (results were presented as expressible fluid), and a salt-induced swelling and centrifugation method (results were presented as percentage of salt-induced water gain). There were no differences for WHC estimated by cooking loss and expressible fluid between the treatments. Only the freezing and thawing treatment resulted in a significant increase in drip loss. The average percentage of salt-induced water gains by the 24-h deboned samples, postdeboning aged 2 h samples, and frozen 2 h sample, which did not differ from each other, were significantly higher than that by the 2-h deboned sample. These results indicate that regardless of method (carcass aging vs. postdeboning aging) and time (aging for 1 d vs. for 7 d), postmortem aging more than 1 d does `not affect WHC of the early deboned samples measured by dripping, cooking, and pressing. However, postmortem carcass aging, postdeboning aging, and freezing and thawing storage can significantly enhance the ability of chicken breast meat to hold added salt water or WHC measured by the salt-induced swelling and centrifuge method. [ABSTRACT FROM AUTHOR]